DENVER (AP) — On Oct. 26, 1967, a missile the size of a telephone pole blew the wing off of John McCain’s Skyhawk dive bomber.

McCain, then a 31-year-old lieutenant commander in the Navy, parachuted out of the plane and landed in a lake in Hanoi, North Vietnam. He broke both arms and a leg in the fall, was dragged from the lake by an angry crowd, and was beaten and bayoneted.

Thus began a harrowing, five-year ordeal that was to define the future senator and presidential candidate’s...